About 1200 litres of blood pass through the kidneys every day but we don't produce anything like this amount of urine. Most of the water is taken back into the body by the kidneys and we produce only 1-1.5 litres of urine each day. The bladder of an adult can hold about 0.25 litres of urine before they feel uncomfortable. The bladder can hold about 0.5 litres before it really has to be emptied, so usually this happens about 5 times a day.
Most people have two kidneys, but it is possible to be healthy with only one. Each kidney is about 15 cm long and weighs 150g. The outside is protected by a tough capsule and inside is an intricate system of fine tubes that take blood in under pressure and filter out useful components, such as sugars and water, and concentrate waste products such as urea for excretion in the urine.
Most people have two kidneys, but it is possible to be healthy with only one. Each kidney is about 15 cm long and weighs 150g. The outside is protected by a tough capsule and inside is an intricate system of fine tubes that take blood in under pressure and filter out useful components, such as sugars and water, and concentrate waste products such as urea for excretion in the urine.
